Recent developments and innovations in the field of recycling used rubber articles, in particular automobile tires, have determined that longstanding problems of disposal of waste rubber may be soluble by new, economically feasible recycling processes. However, new molding techniques are required to fashion useful articles from the recycled material, due to the high pressure and temperature required to effect repolymerization. The molds must be capable of generating, maintaining, and withstanding intense pressure in the mold change, and also must transfer heat evenly and efficiently to the molded material.